1. Field of the Invention
The present invention relates to a data transfer apparatus in a semiconductor memory device for a high speed operation, and more particularly to, an apparatus of controlling data and a data strobe driving signal in a semiconductor memory device and a method of controlling the same, capable of adjusting a setup/hold time of a system by separately controlling data and a data strobe driver.
2. Discussion of Related Art
As a high speed operation memory has been required, it has become a trend that a minimum data deciding time of a data setup/hold time, which has not been a problem in a low speed operation memory, is being decreased by hundreds ps (pico second). The condition makes it difficult to decide data in a high speed operation memory. Actually, a DRAM drives data DQ and a data strobe DQS by the same strength and a system receiving the data inputted by the DRAM uses the DQS as a reference signal to receive the data.
After constructing a system, the system gets a setup/hold time inherently. During this, once the setup/hold time is set, it is seriously difficult to vary it in the system.
In general, it is possible in a low speed operation to transfer a sufficient data by the setup/hold time which has once set, but there may be a problem in a high speed operation. Therefore, it is occurred to reset the setup/hold time in the high speed operation.
Accordingly, if the system which has set causes a trouble, the data and the data strobe strengths are controlled at the same time. It will be described about this conventional art with reference to FIG. 1.
An inputted data signal is driven by a DQ driver 10 and transferred to a DQ pad 30 according to a data strobe signal passed through a delay stage.
In addition, the data strobe signal is driven by a DQS driver 20 and then transferred to a DQS pad 40. The side of receiving the data signal receives the data signal according to the data strobe signal supplied from the DQS pad 40.
As the DQ driver 10 and the DQS driver 20 are controlled by the data strobe signal identically inputted to the drivers at the same time, the conventional art can be impossible to control a data signal at the side of receiving it and an arriving time of a data strobe signal for a receiving reference of the data, separately. As a result, in case of the system which has already set, it is also impossible to minutely control the setup/hold time of the data signal and the data strobe signal.